The objective was to remove around 300 kg of waste in the ports of Vigo, Marín and Gandía throughout 2018, but reality exceeded expectations and more than three tons were recovered from these three ports within the RepescaPlas project, an initiative launched in 2017 by the Plastic Technology Institute (Aimplas), in collaboration with the University of Vigo, through the Ecotox group; the Global Nature Foundation; the Zero Waste Association and the Gandía Fishermen’s Guild. The aim was to collect marine litter on the coasts of Galicia and Valencia to analyze and valorize it in the form of new products and, in this way, move forward towards finding a solution to this problem and its effects on marine biodiversity.
The collection of the garbage was carried out by fishermen from the ports of Vigo, Marín and Gandía, who have removed 3000 kilos over the last few months, both deposited on deep seabeds and floating within the water column. These figures multiply the initial forecast by ten and have allowed the identification and cataloging of 8000 objects, classified according to categories and types with the methodology developed on the ‘Marnoba’ platform.
Among the waste collected in the ports of Marín and Vigo, industrial packaging, plastic sheets and plastic bottles predominate, with 473 and 460 units, respectively. In the case of Gandía, a greater number of food containers and bags were found, both in the “plastic” category, of which 995 and 967 units were removed, respectively. In general, in both the Mediterranean and the Atlantic, plastic objects predominate, but other categories such as metal were also found, with a total of 465 units of beverage cans, or 308 units of clothing and fabrics. In addition, fishing lines, cables and ropes and other fishing objects, such as octopus traps, were also identified, which were found on the Galician coasts.
Ecotoxicological characterization
Some of the collected objects, those classified within the ‘plastic’ category, underwent a characterization process also based on their nature before the material recovery or recycling process proposed in the project. In this sense, an ecotoxicological characterization study was carried out with the selection of three wastes (nets, octopus traps and industrial foils), which were exposed to three marine organisms, specifically sea urchin larvae, microalgae and copepods. All the results were negative, with the exception of one type of fishing net that showed toxicity in the case of sea urchin larvae. The project researchers will analyze this data in detail in 2019 to observe whether this toxicity is due to the material, the additives or by elements that are absorbed by it during its stay in the marine environment.
Finally, and after characterizing the waste according to the type of material, the researchers focused on the plastic fraction to carry out pre-treatment by washing and crushing and experimented with the possibilities of valorization of each type of material. Among these materials, the ‘film’ type -such as low-density polyethylene or polypropylene, among others- presents better results for its recycling or material valorization.
RepescaPlas will continue this year to deepen the studies already carried out with the aim of expanding and consolidating the results, and extending the project to new areas of the Spanish coast. The initiative is being developed in collaboration with the Biodiversity Foundation and the Ministry for the Ecological Transition, through the Pleamar Program, co-financed by the FEMP.
Source: DUVI
